Abstract
Epigenetic, along with genetic mechanisms, is essential for natural evolution and maintenance of specific patterns of gene expression in mammalians. Global epigenetic variation is inherited somatically and unlike genetic variation, it is dynamic and reversible. They are somatically associated with known genetic variations. Recent studies indicate the broad role of epigenetic mechanisms in the initiation and development of cancers, that they are including DNA methylation, histone modifications, nucleosomes changes, non-coding RNAs. The reversible nature of epigenetic changes has led to the emergence of novel epigenetic therapeutic approaches, so that several types of these medications have been approved by the FDA so far. In this review, we discuss the concept of epigenetic changes in diseases, especially cancers, the role of these changes in the onset and progression of cancers and the potential of using this knowledge in designing novel therapeutic strategies.